JP2018007216A - Image reading device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reading device capable of more suppressing a vibration caused by the movement of a member for calibration in a configuration where the movement of the member for calibration in a main scan direction is guided by a shaft member extending in the main scan direction as compared with a configuration where rotation around the shaft member of the member for calibration is not restricted.SOLUTION: The image reading device includes an irradiation part which irradiates a recording medium with light, a detection part which detects the light reflected by the recording medium, a holding member which is movable in the main scan direction of the irradiation part and holds the member for calibration irradiated with the light of the irradiation part, the shaft member which extends in the main scan direction, passes through the holding member, and guides the movement of the holding member in the main scan direction, and a restriction member which extends in the main scan direction and restricts the rotation around the shaft member of the holding member.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an image reading apparatus and an image forming apparatus.

  In an image forming apparatus, an image reading function for reading an image after formation may be provided, and feedback may be provided for color conversion processing control during image formation.

  In Patent Document 1, the shading correction plate disposed on the ball screw is moved in the main scanning direction, which is the axial direction of the ball screw, by rotating the ball screw with a drive motor, and reflected by the shading correction plate. A technique for reading reflected light with a CCD is disclosed.

Japanese Patent Laid-Open No. 01-176158

  According to the technique disclosed in Patent Document 1, the shading correction plate moves with the rotation of the ball screw, and the shading correction plate vibrates (swings around the ball screw) with this movement.

  According to the present invention, in the configuration in which the movement of the calibration member in the main scanning direction is guided by the shaft member extending in the main scanning direction, the calibration member is moved compared to the configuration in which the rotation of the calibration member around the shaft member is not limited. It is an object to obtain an image reading apparatus and an image forming apparatus that can suppress the accompanying vibration.

  The image reading apparatus according to claim 1 is movable in the main scanning direction of the irradiation unit that irradiates the recording medium with light, a detection unit that detects light reflected by the recording medium, and the irradiation unit. A holding member that holds the calibration member that is irradiated with light from the irradiation unit, and an axis that extends in the main scanning direction, penetrates the holding member, and guides the movement of the holding member in the main scanning direction A member, and a limiting member that extends in the main scanning direction and limits rotation of the holding member around the shaft member.

  The image reading device according to claim 2, further comprising a positioning unit that extends in the main scanning direction and that determines a distance from the light source of the irradiation unit, in the image reading device according to claim 1, The holding member has one end as a free end, and includes an elastically deformable holding plate portion that holds the calibration member, and a contact portion that contacts the positioning portion by a restoring force of the holding plate portion. ing.

  According to a third aspect of the present invention, in the image reading apparatus according to the second aspect, the positioning unit is provided in a case constituting the irradiation unit or a guide member that guides conveyance of the recording medium. .

  An image reading apparatus according to a fourth aspect is the image reading apparatus according to any one of the first to third aspects, wherein an air blowing section that blows cooling air to a light source of the irradiation section and the holding member A driving source for moving in the scanning direction, and the driving source is disposed downstream of the light source in the air blowing direction of the air blowing unit.

  An image reading apparatus according to a fifth aspect is the image reading apparatus according to any one of the first to fourth aspects, wherein the holding member moves on the light source side of the irradiation unit with respect to the recording medium.

  The image forming apparatus according to claim 6, wherein an image forming unit that forms an image on a recording medium, and the recording medium on which the image is formed are irradiated with light and the light reflected by the recording medium is detected. And the image reading device according to any one of claims 1 to 5, which reads the image.

  According to the image reading apparatus of the first aspect, in the configuration in which the shaft member extending in the main scanning direction guides the movement of the calibration member in the main scanning direction, the rotation of the calibration member around the shaft member is not limited. In comparison, vibration associated with movement of the calibration member can be suppressed.

  According to the image reading apparatus of the second aspect, it is possible to suppress vibration when the holding member moves in the main scanning direction, as compared with the configuration in which the contact portion of the holding plate portion does not contact the positioning portion.

  According to the image reading apparatus of the third aspect, the distance from the light source of the calibration member (the distance in the amplitude direction) compared to the configuration in which the positioning unit is not provided in the case or the guide member constituting the irradiation unit. Variation can be suppressed.

  According to the image reading apparatus of the fourth aspect, it is possible to suppress the heat of the driving source from being transmitted to the light source as compared with the configuration in which the driving source is disposed upstream of the light source in the blowing direction of the blowing unit.

  According to the image reading apparatus of the fifth aspect, compared with the configuration in which the holding member moves on the side opposite to the light source of the irradiation unit with the recording medium interposed therebetween, it is possible to irradiate the calibration member with light even when the continuous paper is set. .

  According to the image forming apparatus of the sixth aspect, the calibration can be stably performed as compared with the configuration not including the image reading apparatus according to any one of the first to fifth aspects.

1 is a schematic configuration diagram illustrating an example of a configuration of an image forming apparatus according to an embodiment. 1 is a schematic configuration diagram illustrating an example of a configuration of a reading sensor provided in an image forming apparatus according to an embodiment. It is the perspective view which looked at the reading sensor from diagonally downward. FIG. 3 is a perspective view of the inside of a reading sensor viewed from the sub-scanning direction. FIG. 3 is an enlarged view of a portion indicated by an arrow 5 in FIG. 2. It is the perspective view which looked at the holding member from diagonally upward. It is a disassembled perspective view of the holding member shown in FIG. It is a perspective view which shows the modification of a holding member (it is a perspective view corresponding to FIG. 6). It is a perspective view which shows the other modification of a holding member (it is a perspective view corresponding to FIG. 6). It is sectional drawing of the lower part of a reading sensor (it is sectional drawing corresponding to FIG. 5).

  Hereinafter, an example of an image reading apparatus and an image forming apparatus according to an embodiment of the present invention will be described in detail.

(Overall configuration of image forming apparatus)
As shown in FIG. 1, an image forming apparatus 10 according to the present embodiment selectively forms a full-color image and a monochrome image, and includes a first housing 10 </ b> A that is an image forming unit, and a first housing. And a second housing 10B connected to 10A. An image processing unit 13 that performs image processing on image data supplied from an external device such as a computer is provided on the upper portion of the second housing 10B.

  On the upper part of the first housing 10A, yellow (Y), magenta (M), cyan (C), and black (K) as normal colors and gold as a first special color that is a specific color Toner cartridges 14Y, 14M, 14C, 14K, 14G, and 14S are provided that store toners of silver (S) as the second special color (G) and a specific color.

  In this embodiment, gold and silver are exemplified as the first special color and the second special color. However, as the first special color and the second special color, for example, white (W), clear (CL), etc. It may be used.

  In the following description, the first special color (G), the second special color (S), yellow (Y), magenta (M), cyan (C), and black (K) are distinguished for each component. Will be described by adding a letter of G, S, Y, M, C, or K after a number as a symbol. When the first special color (G), the second special color (S), yellow (Y), magenta (M), cyan (C), and black (K) are not distinguished, G, S, Y, M , C and K are omitted.

  Under the toner cartridges 14, six image forming units 16 G, 16 S, 16 Y, 16 M, 16 C, and 16 K (collectively referred to as “image forming units 16”) corresponding to the toners of the respective colors are placed in the toner cartridges 14. It is provided to correspond.

  Exposure devices 40G, 40S, 40Y, 40M, 40C, and 40K (collectively referred to as “exposure device 40”) provided for each image forming unit 16 are images that have been subjected to image processing by the image processing unit 13 described above. Data is received from the image processing unit 13. Then, a light beam modulated in accordance with the image data is irradiated to image holders 18G, 18S, 18Y, 18M, 18C, and 18K (hereinafter collectively referred to as “image holder 18”). .

  In each image forming unit 16, an electrostatic latent image is formed on each image carrier 18 by irradiating each image carrier 18 with the light beam L from each exposure device 40.

  Around each image carrier 18, a corona discharge (non-contact charging) scorotron charger that charges the image carrier 18 and an electrostatic latent image formed on the image carrier 18 by the exposure device 40 are developed. A developing device that develops with toner, which is an example of an agent, a blade that removes the developer remaining on the image carrier 18 after transfer, and a static eliminator that performs static elimination by irradiating the image carrier 18 after transfer with light. Is provided. The scorotron charger, the developing device, the blade, and the static eliminator are arranged in this order from the upstream side to the downstream side in the rotation direction of the image carrier 18 so as to face the surface of the image carrier 18.

  A transfer unit 32 is provided below each image forming unit 16. The transfer unit 32 includes an annular intermediate transfer belt 34 that is in contact with each image carrier 18, and primary transfer rolls 36 </ b> G, 36 </ b> S, 36 </ b> Y that multiplex-transfer toner images formed on each image carrier 18 onto the intermediate transfer belt 34. 36M, 36C, 36K (collectively referred to as “primary transfer roll 36”).

  The intermediate transfer belt 34 includes a drive roll 38 that is driven by a motor (not shown), a tension applying roll 41 that applies tension to the intermediate transfer belt 34, an opposing roll 42 that faces a secondary transfer roll 62 described below, It is wound around a plurality of winding rolls 44. And it is circularly moved in one direction (counterclockwise direction in FIG. 1) by the drive roll 38.

  Each primary transfer roll 36 is disposed opposite to the image carrier 18 of each image forming unit 16 with the intermediate transfer belt 34 interposed therebetween. The primary transfer roll 36 is applied with a transfer bias voltage having a polarity opposite to the toner polarity by a power supply unit (not shown). With this configuration, the toner image formed on the image carrier 18 is transferred to the intermediate transfer belt 34.

  On the opposite side of the drive roll 38 across the intermediate transfer belt 34, there is provided a removing device 46 that removes residual toner, paper dust and the like on the intermediate transfer belt 34 by bringing the blade into contact with the intermediate transfer belt 34. .

  Below the transfer unit 32, a plurality of recording medium storage units 48 that store recording media P such as paper are provided. Each of the recording medium accommodating portions 48 can be pulled out from the first housing 10A. A delivery roll 52 that feeds the recording medium P from each recording medium container 48 to the transport path 60 is provided above one end side (right side in front view in FIG. 1) of each recording medium container 48.

  In each recording medium accommodating portion 48, a bottom plate 50 on which the recording medium P is placed is provided. The bottom plate 50 is lowered by an instruction from a control means (not shown) when the recording medium accommodating portion 48 is pulled out from the first housing 10A. When the bottom plate 50 is lowered, a space in which the user replenishes the recording medium P is formed in the recording medium accommodating portion 48.

  When the recording medium accommodating portion 48 pulled out from the first housing 10A is attached to the first housing 10A, the bottom plate 50 is raised by an instruction from the control means. As the bottom plate 50 moves up, the uppermost recording medium P placed on the bottom plate 50 and the delivery roll 52 come into contact with each other.

  On the downstream side in the paper conveyance direction of the delivery roll 52 (hereinafter sometimes simply referred to as “downstream side”), there is a separation roll 56 that separates the recording media P delivered from the recording medium accommodating portion 48 one by one. Is provided. A plurality of transport rolls 54 that transport the recording medium P downstream in the transport direction are provided on the downstream side of the separation roll 56.

  The conveyance path 60 provided between the recording medium storage unit 48 and the transfer unit 32 inverts the recording medium P sent out from the recording medium storage unit 48 to the left side when viewed from the front in FIG. Further, the second direction changing portion 60B extends to the transfer position T between the secondary transfer roll 62 and the opposing roll 42 so as to be reversed to the right in the front view in FIG.

  The secondary transfer roll 62 is applied with a transfer bias voltage having a polarity opposite to the toner polarity by a power feeding unit (not shown). With this configuration, the toner images of each color that have been multiplex-transferred onto the intermediate transfer belt 34 are secondarily transferred onto the recording medium P that has been transported along the transport path 60 by the secondary transfer roll 62.

  A preliminary path 66 extending from the side surface of the first housing 10 </ b> A is provided so as to join the second direction changing portion 60 </ b> B of the transport path 60. The recording medium P sent out from another sheet storage unit (not shown) arranged adjacent to the first housing 10 </ b> A can enter the transport path 60 through the spare path 66.

  On the downstream side of the transfer position T, a plurality of conveying belts 70 that convey the recording medium P on which the toner image has been transferred toward the second casing 10B are provided in the first casing 10A, and are conveyed to the conveying belt 70. A transport belt 80 that transports the recording medium P to the downstream side is provided in the second housing 10B.

  Each of the plurality of conveyor belts 70 and the conveyor belt 80 is formed in an annular shape, and is wound around a pair of winding rolls 72. The pair of winding rolls 72 are respectively arranged on the upstream side and the downstream side in the conveyance direction of the recording medium P, and when one of them is driven to rotate, the conveyance belt 70 (conveyance belt 80) moves in one direction (in FIG. 1). Cycle in the clockwise direction.

  A fixing unit 82 for fixing the toner image transferred onto the surface of the recording medium P to the recording medium P with heat and pressure is provided on the downstream side of the conveyance belt 80.

  The fixing unit 82 includes a fixing belt 84 and a pressure roll 88 disposed so as to contact the fixing belt 84 from below. A fixing unit N is formed between the fixing belt 84 and the pressure roll 88 to fix the toner image by pressurizing and heating the recording medium P.

The fixing belt 84 is formed in an annular shape and is wound around the drive roll 89 and the driven roll 90. The drive roll 89 faces the pressure roll 88 from above,
The driven roll 90 is disposed above the drive roll 89.

  Each of the driving roll 89 and the driven roll 90 includes a heating unit such as a halogen heater. As a result, the fixing belt 84 is heated.

  As shown in FIG. 1, a conveyance belt 108 is provided on the downstream side of the fixing unit 82 to convey the recording medium P sent from the fixing unit 82 to the downstream side.

  A cooling unit 110 that cools the recording medium P heated by the fixing unit 82 is provided on the downstream side of the conveyance belt 108.

  The cooling unit 110 includes an absorption device 112 that absorbs the heat of the recording medium P, and a pressing device 114 that presses the recording medium P against the absorption device 112. The absorption device 112 is disposed on one side (upper side in FIG. 1) with respect to the conveyance path 60, and the pressing device 114 is disposed on the other side (lower side in FIG. 1).

  The absorption device 112 includes an annular absorption belt 116 that contacts the recording medium P and absorbs the heat of the recording medium P. The absorption belt 116 is wound around a driving roll 120 that transmits a driving force to the absorption belt 116 and a plurality of winding rolls 118.

  A heat sink 122 made of, for example, an aluminum material is provided on the inner peripheral side of the absorption belt 116 to dissipate the heat absorbed by the absorption belt 116 in contact with the absorption belt 116 in a planar shape.

  Further, a fan 128 for removing heat from the heat sink 122 and discharging hot air to the outside is disposed on the back side of the second housing 10B (the back side of the paper surface shown in FIG. 1).

  The pressing device 114 that presses the recording medium P against the absorbing device 112 includes an annular pressing belt 130 that conveys the recording medium P while pressing the recording medium P against the absorbing belt 116. The pressing belt 130 is wound around a plurality of winding rolls 132.

  On the downstream side of the cooling unit 110, there is provided a correction device 140 that conveys the recording medium P and corrects the curl of the recording medium P.

  On the downstream side of the correction device 140, a reading sensor 200 is provided as an example of an image reading device that detects a toner density defect, an image defect, an image position defect, and the like of the toner image fixed on the recording medium P. Details of the reading sensor 200 will be described later.

  On the downstream side of the reading sensor 200, a discharge roll 198 that discharges the recording medium P having an image formed on one side thereof to a discharge unit 196 attached to the side surface of the second housing 10B is provided.

  On the other hand, when images are formed on both sides, the recording medium P sent from the reading sensor 200 is conveyed to a reversing path 194 provided on the downstream side of the reading sensor 200.

  The reversing path 194 includes a branch path 194A that branches from the transport path 60, a paper transport path 194B that transports the recording medium P transported along the branch path 194A toward the first housing 10A, and a paper transport path. A reversing path 194C is provided that reverses the recording medium P conveyed along 194B in the reverse direction to carry it in a switchback manner and reverse the front and back.

  With this configuration, the recording medium P that is switched back and conveyed by the reverse path 194C is conveyed toward the first housing 10A, and further enters the conveyance path 60 provided above the recording medium container 48, and is transferred to the transfer position. It is sent to T again.

Next, an image forming process of the image forming apparatus 10 will be described.
Image data that has been subjected to image processing by the image processing unit 13 is sent to each exposure device 40. In each exposure device 40, each light beam L is emitted according to the image data and exposed to each image carrier 18 charged by the scorotron charger 20, and an electrostatic latent image is formed.

  The electrostatic latent image formed on the image carrier 18 is developed by the developing device 22 and is first special color (G), second special color (S), yellow (Y), magenta (M), cyan (C ) And black (K) toner images are formed.

  As shown in FIG. 1, each color toner image formed on the image carrier 18 of each of the image forming units 16G, 16V, 16Y, 16M, 16C, and 16K is composed of six primary transfer rolls 36G, 36S, 36Y, and 36M. , 36C, and 36K, multiple transfer is sequentially performed on the intermediate transfer belt.

  The toner images of the respective colors that have been multiplex-transferred onto the intermediate transfer belt 34 are secondarily transferred onto the recording medium P conveyed from the recording medium accommodating portion 48 by the secondary transfer roll 62. The recording medium P onto which the toner image has been transferred is transported toward the fixing unit 82 provided inside the second housing 10B by the transport belt 70.

  The toner images of the respective colors on the recording medium P are fixed on the recording medium P by being heated and pressurized by the fixing unit 82. Further, the recording medium P on which the toner image is fixed is cooled by passing through the cooling unit 110 and then sent to the correction device 140 to correct the curvature generated in the recording medium P.

  The recording medium P whose curvature is corrected is discharged to the discharge unit 196 by the discharge roll 198 after an image defect or the like is detected by the reading sensor 200.

  On the other hand, when an image is formed on a non-image surface where no image is formed (in the case of double-sided printing), the recording medium P is reversed by the reversing path 194 after passing through the reading sensor 200. Then, the toner image is sent to a conveyance path 60 provided above the recording medium container 48, and a toner image is formed on the back surface in the above-described procedure.

  In the image forming apparatus 10 according to the present embodiment, components (image forming units 16G and 16S, exposure devices 40G and 40S, toner cartridges 14G and 14S, toner images) for forming images of the first special color and the second special color are used. The primary transfer rolls 36G and 36S) are configured to be attachable to the first housing 10A as additional components according to the user's selection.

(Reading sensor 200)
The image forming apparatus 10 according to this embodiment includes the reading sensor 200 on the downstream side of the correction device 140 as described above. The reading sensor 200 is used to detect whether an image formed on the recording medium P by the image forming unit 16 is abnormal.

  In this case, the reading sensor 200 has a function as a measurement unit of gradation reproducibility and color reproducibility of the image forming unit 16. In addition, the reading sensor 200 may be calibrated regularly or irregularly in order to maintain the function of the measuring unit normally.

  In the following description, the length direction of the image forming apparatus 10 (sub-scanning direction that is the conveyance direction of the recording medium P) is the X direction, the height direction of the apparatus is the Y direction, and the depth direction of the apparatus (main scanning direction) is Z. The direction is assumed (see FIGS. 1 and 2). The X direction, the Y direction, and the Z direction are orthogonal to each other. Further, in the following, “front” refers to the surface of the apparatus shown in FIG. 1, and “back” refers to the surface of the apparatus opposite to the front.

  As shown in FIG. 2, a reading sensor 200, which is an example of an image reading apparatus, detects an irradiation unit 202 that irradiates light toward a recording medium P on which an image is recorded, and light reflected by the recording medium P. And an imaging unit 208 as an example of the detection unit. The imaging unit 208 includes a CCD sensor 204 and an imaging optical system 206 that images the reflected light reflected by the recording medium P onto the CCD sensor 204.

  The CCD sensor 204 according to the present embodiment includes a plurality of light receiving elements (for example, photodiodes) arranged along a direction corresponding to the main scanning direction, and includes a red image sensor and a green image. A sensor and a blue image sensor are provided. Each color image sensor is provided with a filter that transmits light of each color component on the light receiving surface of the light receiving element. Each color image sensor outputs the electric charge accumulated according to the amount of each color component of the light received by the light receiving element as a signal.

  The irradiation unit 202 is disposed on the upper side of the conveyance path 60 of the recording medium P, and has a pair of lamps 212A and 212B that are elongated in the Z direction (main scanning direction). ”).

  As the lamp 212, for example, a fluorescent lamp, a xenon lamp, or a plurality of white LEDs (not shown) arranged along the main scanning direction is used.

  The length of the irradiation range of the lamp 212 is made larger than the width of the maximum recording medium P to be conveyed. The lamp 212 is arranged symmetrically with respect to the optical axis OA (designed optical axis) that is reflected by the recording medium P and travels toward the image forming unit 208.

  The light irradiated from the lamp 212 is configured to be irradiated to the irradiation position D of the transparent window glass 286 on the conveyance path 60 between the lamps 212A and 212B.

  Further, the imaging optical system 206 includes a first mirror 214 that reflects the light guided along the optical axis OA in the X direction (downstream in the conveyance direction of the recording medium P in the first embodiment), and a first mirror 214. The second mirror 216 that reflects the light reflected by the mirror 214 upward, the third mirror 218 that reflects the light reflected by the second mirror 216 upstream in the conveyance direction of the recording medium P, and the third mirror 218 reflected. A lens 220 for condensing (imaging) light on the CCD sensor 204 and a light amount diaphragm unit 224 (224L, 224S, 224U)) are mainly configured.

  The length of the first mirror 214 in the Z direction is larger than the width of the maximum recording medium P. The first mirror 214, the second mirror 216, and the third mirror 218 are respectively focused (condensed) while reflecting the reflected light of the recording medium P incident on the imaging optical system 206 in the Z direction (main scanning direction). ) It is designed to reflect. Thus, the reflected light from each part in the width direction of the recording medium P is incident on the substantially cylindrical lens 220.

  The reading sensor 200 is configured such that the CCD sensor 204 outputs (feeds back) the imaged light, that is, a signal corresponding to the image density, to the control device 192 (see FIG. 1) of the image forming apparatus 10. The control device 192 performs processing for correcting an image formed in the image forming unit 16 based on a signal input from the reading sensor 200. In the image forming apparatus 10, as an example, the intensity of light irradiated by the exposure device 40, the image formation position, and the like are corrected based on a signal from the reading sensor 200.

  Further, the reading sensor 200 is movable in the main scanning direction (Z direction), the holding member 232 holding the calibration member 230 irradiated with light from the irradiation unit 202, and the holding member 232 in the main scanning direction. A shaft member 234 that guides the movement and a limiting member 236 that restricts rotation of the holding member 232 around the shaft member 234 are provided.

  The shaft member 234 is a shaft having a circular cross section, and is disposed so as to extend along the main scanning direction. Both end portions of the shaft member 234 are fixed to side walls 226 </ b> A facing the main scanning direction of the lower case 226 constituting the irradiation unit 202 of the reading sensor 200. The reading sensor 200 includes an upper case 228 and a lower case 226, and the upper case 228 constitutes an image forming unit 208.

  The limiting member 236 is a shaft having a circular cross section, and is arranged so as to extend along the main scanning direction at a position away from the shaft member 234 in the apparatus height direction (Y direction). Both ends of the limiting member 236 are fixed to the side wall 226A of the lower case 226.

  The holding member 232 is provided at a lower portion of the slide portion 242 in which a through hole 238 through which the shaft member 234 passes and a through hole 240 through which the limiting member 236 passes, and one end 244A is a free end, And an elastically deformable holding plate portion 244 for holding the calibration member 230.

  As shown in FIGS. 5 and 6, a through hole 240 is formed in the upper part of the slide part 242, and a through hole 238 is formed in the lower part. The through hole 240 is a long hole whose longitudinal direction is the device height direction. An attachment hole 250 for attaching a connecting member 248 for connecting the slide part 242 to a belt 246 described later is formed on the upper surface of the slide part 242.

  As shown in FIGS. 6 and 7, the holding plate portion 244 is formed by bending an elastically deformable metal plate into a substantially L shape, and the vertical plate portion 252 is formed below the slide portion 242 with a screw member 253. And the horizontal plate portion 254 is disposed so as to face the window glass 286. Further, a calibration member 230 is attached to the upper surface 254A of the horizontal plate portion 254.

In the vicinity of one end 244A, which is the end of the horizontal plate portion 254 opposite to the vertical plate portion 252, a protruding portion 256 that protrudes from the upper surface 254A in the apparatus height direction is formed. The protrusion 256 is configured to contact the lower surface 286A of the window glass 286. Specifically, as illustrated in FIG. 5, the protruding portion 256 is pressed against the lower surface 286 </ b> A of the window glass 286 by the restoring force of the bent holding plate portion 244. In addition, the window glass 286 of this embodiment is an example of the positioning part in this invention.
Here, the window glass 286 forms the lower end 226B of the lower case 226, and the distance from the lamp 212 is determined. Therefore, the distance from the lamp 212 to the calibration member 230 becomes a predetermined value by bringing the protruding portion 256 of the horizontal plate portion 254 into contact with the lower surface 286A of the window glass 286.

  Further, as shown in FIG. 5, the horizontal plate portion 254 of the holding plate portion 244 moves on the lamp 212 side relative to the recording medium P.

  As shown in FIG. 4, the lower case 226 is provided with a moving force applying mechanism 258 that applies a moving force in the main scanning direction to the holding member 232.

  The moving force applying mechanism 258 includes a drive motor 260 as an example of a drive source in which the sub-scanning direction is the axial direction of the motor shaft 260A, a gear 262 for the belt 246 attached to the motor shaft 260A, and the drive motor 260. On the other hand, a pulley 264 that is disposed at a position away from the main scanning direction and whose sub-scanning direction is the rotation axis direction, and a belt 246 that is wound around the gear 262 and the pulley 264 are provided.

  The drive motor 260 is fixed to the side wall 226A of the lower case 226 via a bracket (not shown). The drive motor 260 is controlled by the control device 192.

  The pulley 264 is rotatably supported by a support member 266 fixed to the side wall 226A. The support member 266 can adjust the position of the rotation center of the pulley 264 in the main scanning direction. By adjusting the position of the rotation center of the pulley 264 in the main scanning direction, the tension of the belt 246 wound around the gear 262 and the pulley 264 can be adjusted.

  Here, when the drive motor 260 is operated, the belt 246 circulates between the gear 262 and the pulley 264, and the holding member 232 connected to the belt 246 via the connecting member 248 is moved in the main scanning direction by the shaft member 234. Move while being guided.

  Note that the holding member 232 can move outward in the main scanning direction from the end in the width direction of the largest recording medium P to be conveyed. Therefore, when calibration is not performed, the holding member 232 can be retracted from the conveyance line of the recording medium P.

  The calibration member 230 is for calibration of the imaging optical system 206, and is a reference white film from which a predetermined signal is output from the imaging optical system 206.

  In addition, as shown in FIG. 2, the reading sensor 200 is provided in a cooling fan 268 as an example of a blower that blows cooling air to the lamp 212, and the upper case 228 and the lower case 226. And a guide duct 270 for guiding.

  The cooling fan 268 is disposed below the air intake 272 formed on the upper surface of the upper case 228, and the air taken in from the air intake 272 is blown downward through the guide duct 270 as cooling air. Yes.

  The guide duct 270 is provided from the lower side of the cooling fan 268 of the upper case 228 to the vicinity of the lamp 212A of the lower case 226. Cooling air is blown through the guide duct 270 to one of the lamps 212B (the lamp 212 on the downstream side in the sub-scanning direction).

  Here, the cooling air guided to the one lamp 212A through the guide duct 270 flows to the other lamp 212B through the internal space 274 in which the lamp 212 of the lower case 226 is disposed. Thereafter, the cooling air flows to the drive motor 260 positioned above the other lamp 212B. That is, the drive motor 260 is arranged downstream of the other lamp 212B in the air blowing direction. In addition, in FIG. 2, the ventilation direction of cooling air is shown by arrow CA.

The operation of this embodiment will be described.
As shown in FIG. 3, the reading sensor 200 irradiates the recording medium P passing under the irradiation unit 202 with a pair of lamps 212. The light reflected by the recording medium P is guided to the imaging unit 208 along the optical axis OA, and is imaged on the CCD sensor 204 by the imaging optical system 206 of the imaging unit 208. The CCD sensor 204 outputs a signal corresponding to the image density for each image position to the control device 192 of the image forming apparatus 10. The control device 192 corrects the image density, the image forming position, and the like based on the signal from the CCD sensor 204.

  On the other hand, when the CCD sensor 204 constituting the reading sensor 200 is calibrated, first, the drive motor 260 is operated to move the calibration member 230 together with the holding member 232 in the main scanning direction. The CCD sensor 204 is adjusted so that a shading correction signal for correcting the light amount distribution in the Z direction (main scanning direction) is output. Here, the holding member 232 moves in the main scanning direction while being guided by the shaft member 234, and the light reflected by the calibration member 230 is detected by the CCD sensor 204. At this time, the rotation of the holding member 232 around the shaft member 234 (in other words, rotation around the shaft member 234) is restricted by the limiting member 236 that passes through the through hole 240 of the holding member 232. Thereby, in the reading sensor 200, for example, the vibration accompanying the movement of the calibration member 230 can be suppressed as compared with a configuration in which the rotation of the holding member 232 around the shaft member 234 is not limited.

  Further, when the holding member 232 is moved, the protruding portion 256 of the holding plate portion 244 is in contact with the lower surface 286A of the window glass 286, and therefore, for example, the holding member 232 is moved in the main scanning direction as compared with a configuration in which no contact is made. Vibration at the time can be suppressed. In other words, fluctuations in the distance (distance in the amplitude direction) of the calibration member 230 from the lamp 212 can be suppressed. In particular, since the window glass 286 forms the bottom of the lower case 226 of the lamp 212 and the distance from the lamp 212 is determined in advance, the variation of the distance of the calibration member 230 from the lamp 212 is effectively reduced. Can be suppressed.

  In this embodiment, since the drive motor 260 is arranged downstream of the lamp 212 in the air blowing direction of the cooling fan 268, for example, the heat of the drive motor 260 is higher than that of the arrangement arranged upstream of the air blowing direction. Transmission to 212 can be suppressed.

  Furthermore, in this embodiment, since the holding member 232 (specifically, the calibration member 230 provided on the holding plate portion 244) moves on the lamp 212 side with respect to the recording medium P, the holding member 232 is, for example, Compared to the configuration in which the recording medium P is moved on the opposite side of the lamp 212, the calibration member 230 can be irradiated with light even when the recording medium P is a continuous paper sheet that is long in the longitudinal direction.

Furthermore, since the image forming apparatus 10 of the present embodiment includes the reading sensor 200, for example, the calibration can be stably performed as compared with a configuration that does not include the reading sensor 200.
Furthermore, in the image forming apparatus 10 of the present embodiment, the lamp 212 and the calibration member 230 are on the same side as viewed from the conveyance path 60 of the recording medium P, so that the lamp and the calibration member are in the recording medium P. Compared with the configuration on the opposite side as viewed from the conveyance path (configuration in which the recording medium passes between the lamp and the calibration member), the apparatus can be downsized.

  In the above-described embodiment, the protruding portion 256 is formed on the horizontal plate portion 254 of the holding plate portion 244, but the present invention is not limited to this configuration. For example, as shown in FIG. 8, the protruding portion 256 may not be formed on the horizontal plate portion 254. In addition, instead of forming the protruding portion 256 on the horizontal plate portion 254, a protruding portion that extends continuously in the main scanning direction is formed on the lower surface 286A of the window glass 286, and the horizontal plate portion 254 is formed on this protruding portion. Alternatively, the upper surface 254A may be in contact with each other.

  In the above-described embodiment, the protruding portion 256 of the holding plate portion 244 is configured to contact the lower surface 286A of the window glass 286, but the present invention is not limited to this configuration. For example, the protruding portion 256 of the holding plate portion 244 may be brought into contact with a wall surface continuously extending in the main scanning direction of the lower case 226. Further, the upper surface 254A of the horizontal plate portion 254 may be brought into contact with a wall surface continuously extending in the main scanning direction of the lower case 226 without forming the protruding portion 256 on the horizontal plate portion 254 of the holding plate portion 244. Furthermore, as shown in FIG. 10, a guide member that forms a protruding portion 276 on the lower surface 254 </ b> B of the horizontal plate portion 254 of the holding plate portion 244 and is disposed opposite to the window glass 286 to guide the conveyance direction of the recording medium P. As an example, the upper surface 278A of the chute 278 may be brought into contact.

  In the above-described embodiment, the entire calibration member 230 is a white film, but the present invention is not limited to this configuration. For example, as shown in FIG. 9, a part of the calibration member 230 is a white film, and the other part is subjected to a reference color pattern in which a predetermined signal is output from the imaging optical system 206 according to each color. It is good also as a made film.

  Further, when a plurality of white LEDs arranged in the main scanning direction are used as the lamp 212, for example, a configuration may be adopted in which the white LEDs located above the calibration member 230 moving in the main scanning direction emit light. Good.

  The embodiments of the present invention have been described above with reference to the embodiments. However, these embodiments are merely examples, and various modifications can be made without departing from the scope of the invention, and the order of the manufacturing steps can be changed as appropriate. Is possible. It goes without saying that the scope of rights of the present invention is not limited to these embodiments.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 16 Image forming unit (image forming part)
200 Reading sensor (image reading device)
202 Irradiation unit 208 Imaging unit (detection unit)
212 Lamp (light source)
226 Lower case (case)
230 Calibration member 232 Holding member 234 Shaft member 236 Limiting member 244 Holding plate portion 244A One end 256 Protruding portion 260 Drive motor (drive source)
268 Cooling fan (blower)
276 Protruding part 278 Chute (guide member)
CA Blowing direction L Light beam (light)
P Recording medium

Claims (6)

An irradiation unit for irradiating the recording medium with light;
A detector for detecting light reflected by the recording medium;
A holding member that holds a calibration member that is movable in a main scanning direction of the irradiation unit and is irradiated with light of the irradiation unit;
A shaft member extending in the main scanning direction, penetrating the holding member, and guiding movement of the holding member in the main scanning direction;
A restricting member extending in the main scanning direction and restricting rotation of the holding member around the shaft member;
An image reading apparatus. A positioning portion extending in the main scanning direction and having a fixed distance from the light source of the irradiation portion;
The holding member has a free end, and includes an elastically deformable holding plate portion that holds the calibration member, and a contact portion that contacts the positioning portion by a restoring force of the holding plate portion. The image reading apparatus according to claim 1, wherein   The image reading apparatus according to claim 2, wherein the positioning unit is provided in a case constituting the irradiation unit or a guide member that guides conveyance of the recording medium. A blower for blowing cooling air to the light source of the irradiation unit;
A drive source for moving the holding member in the main scanning direction;
Have
The image reading apparatus according to claim 1, wherein the drive source is disposed downstream of the light source in a blowing direction of the blowing unit.   The image reading apparatus according to claim 1, wherein the holding member moves closer to the light source side of the irradiation unit than the recording medium. An image forming unit for forming an image on a recording medium;
The image reading apparatus according to claim 1, wherein the image is read by irradiating the recording medium on which the image is formed, detecting the light reflected by the recording medium, and reading the image. ,
An image forming apparatus.